Safety ladder



Feb. 14, 1967 w. BOUWMEESTER ETAL 3,

SAFETY LADDER Filed Oct. 7, 1964 2 Sheets-Sheet 1 INVENTORS WILLIAMBOUWMEESTER ABRAH AM BE R G 4 ATTORNEYS 1967 w. BOUWMEESTER ETAL 3,

SAFETY LADDER Filed Oct. 7, 1964' 2 Sheets-Sheet 2 INVENTORWILLIAMBOUWMEESTER BYABRAHAM BERG 7774 ATTORNEYS United States Patent3,303,906 SAFETY LADDER William Bouwmeester, Juniper St., and AbrahamBerg, 9 Ingram Drive, both of Hicksville, N.Y. 11801 Filed Oct. 7, 1964,Ser. No. 402,183 6 Claims. (Cl. 182161) This invention relates to aladder for use in conjunction with pools, tanks or other similarstructures to provide steps for access to the pool or tank which stepsautomatically retract upon disuse so that a smooth surface is presentedin order to prevent children or other unauthorized persons from usingthe ladder inadvertently or otherwise unless they understand itsoperation.

The primary purpose of this invention is to provide access to a pool ortank and at the same time furnish a structure which will substantiallyprevent small children from using the ladder without adult aid therebylessening the possibility of accidents.

The object of our invention is to provide a ladder in which a set ofsteps may be made operable and in which the steps, after use,automatically and slowly resume their original inaccessible position.

A further object is to provide a ladder of the character described inwhich actuation of a single handle causes a set of steps to assume anoperative position and, when pressure is released from the steps, toresume their original locked position.

Another object is to provide a structure of the character described inwhich a set of the steps may be operated by hydraulic means.

A further object is to provide a ladder of the character described inwhich a set of the steps are first locked in operative position, and ata predetermined time, are unlocked from said position and returned totheir original locked position.

A further object is to provide a structure in which the above and otherobjects may effectively be attained as will appear from the detailedspecification which follows:

Broadly our invention comprises a ladder in which the steps may bemanually placed in usable position through the operation of a singlehandle and in which the steps will automatically assume an inoperativeposition when weight on the first-named steps has been removedtherefrom.

Practical embodiments of my invention are illustrated in theaccompanying drawings in which:

FIG. 1 represents, in side elevation, a ladder constructed according toour invention and placed with respect to a pool or tank so that accessthereinto by means of the ladder is provided;

FIG. 2 represents an end view of the ladder illustrated in FIG. 1;

FIG. 3 represents a portion of the ladder modified to be operated by ahydraulic mechanism, said portion being partly in section and partlybroken away;

FIG. 4 represents a fragmentary section on an enlarged scale taken onthe line IVIV of FIG. 2, looking in the direction of the arrows, theoperating handle having been removed;

FIG. 5 represents an end view of the fragment shown in FIG. 4; and

FIG. 6 represents an end bracket, shown in detail, removed from itssupporting structure.

Referring to the drawings in which similar parts are given the samenumerals, a pair of front longitudinal supporting members is denoted by23 and a pair of rear supporting longitudinal members is denoted by 24.These parts are held in the desired angular relationship by two endpieces 25 and movable steps 10 are spaced between members 28 to presenta normally fiat surface.

3,303,906 Patented Feb. 14, 1967 Pivoted on a rod 2 is a handle 1 whichturns the rod 2 said rod being supported in elements 29, to throw thelever 3 and the latter, in turn, actuates the lever 4 which is connectedthereto to pull down the longitudinal member 5 against the tension ofspring 14 which is mounted at one end on the horizontal 28 and passesaround a pulley 7 on the member 5. (See FIG. 4.) The other end of spring14 is attached to a bracket 27 on the bottom of top step 12.

Also attached to the member 5, through arms 9 pivoted thereon, are thesteps 10. Said steps 10 are normally pivoted at the other end in theside longitudinals 23 as is shown in FIGS. 1, 3 and 4.

Also attached to bracket 27 on the bottom of the step 12 is a spring 15which is extended over and across the rod 2 and said spring is afiixedat its other end to the member 3 for purposes set forth below.

The operation of handle 1 rotates rod 2 which actuates theinterconnected members 3 and 4 to cause a downward swing of element 5.Due to said downward motion the steps 10 are swung until the partsassume the positions shown in FIG. 4 where the angle iron 11 engages thetop step 12 at which time the steps 10 are temporarily in theirhorizontal or usable position on elements 9.

When the weight of the user has been removed from the last of steps 10,spring 14, operating around pulley 7 on member 5 will cause member 5 torise and this will insure the pivoting of steps 10 in members 23 to aposition in which they are in parallel with said members 23,intermediate elements 28 and with each other. The air or other fluidcylinder 13 acts as a buffer against the force of spring 14 and allowsthe steps to move slowly to their initial position. It will thus be seenthat no step 10 will move while any step 10 is being used but all willstart to move when the weight of the user has been removed from the laststep 10.

The locking of the steps in inoperative position is aided by the spring15 which insured that the latch mechanism, including the members 3 and4, has gone past the center position as is illustrated in FIGS. 3 and 4.

A modified form of our invention is shown in FIG. 3 in which a member20, and a hydraulic cylinder 21 provided with a piston 21a pivoted tomember 20 in order to operate same, are used as replacement for thehandle 1.

An operating valve 22 permits water under pressure, as from the hose 26,to operate the piston 21:: through the cylinder 21 which will causemember 20 to actuate levers 3 and 4 and swing the steps 10 to theirusable position as was described above.

It will be understood that the operation of the mechanism and thelocation of the steps is substantially identical in the two structuresexcept as outlined immediately above.

In this modified form, illustrated in FIG. 3, when the weight of theuser has been removed from the steps 10 the springs 14 and 15 will causethe steps to return to their original position with respect to members23 by lifting members 5 and forcing piston 21a back into cylinder 21which is provided with a small release hole (not shown) in order tobleed the cylinder through outer hose 6.

When one desires to leave the tank this is done by ascending thepermanent steps denoted by 16 which are used until the handle 1, or thehydraulic mechanism, is actuated to cause the steps 10 again to move tousable position. When the weight of the user has been again removed, thesteps 10 will resume their original position.

It will be seen from the above that we have provided a substantiallyfool-proof ladder for use in connection with pools, tanks or the like inorder that the chances for accidents may be minimized and the structuremay be operated only by those having knowledge of its opera tion.

It is contemplated that the operating mechanism will normally be placedbeyond the reach of children.

Since it is evident that various changes may be made in the form,construction and arrangement of the several parts without departing fromthe spirit and scope of our invention, we do not intend to be limited tothe specific embodiments herein shown and described except as set forthin the appended claims.

What We claim is:

1. In a safety ladder structure comprising a pair of opposed,longitudinal, supporting members, a set of movable steps in said pair ofmembers, a linkage operatively connected to the movable steps to providefor movement of the latter between usable and inoperative positions,locking means connected to said linkage to lock said steps ininoperative position, and means manually actuated to simultaneouslyrelease the locking means and operate said linkage to place the steps inoperative position.

2. In a structure of the character described comprising a pair ofopposed longitudinal supporting members, a set of steps movable betweenusable and inoperative positions in said pair of members, operativemeans connected to the movable steps for placing the latter in a usableposition, manual means comprising a hand lever for actuating saidlast-na1ned means, said operative means comprising interconnected leversaffixed to the hand lever and movable steps, locking means cooperatingwith said interconnected levers for urging the latter into a lockedposition to hold the steps in inoperative position, and further meansacting on said operative means for restoring the movable steps to theiroriginal inoperative position when the weight of a user has been removedtherefrom.

3. In a structure according to claim 2 in which the means for restoringthe steps to their inoperative position comprises a spring biasing thesteps to their inoperative position, said locking means comprising aspring afiixed to said interconnected levers for holding the latter insaid locked position.

4. A structure of the character described comprising pairs of opposedlongitudinal supporting members, a set of movable steps normally lockedin parallel with one pair of longitudinal supporting members, a set offixed steps in the opposed pair of supporting members, means forswinging the first-named set of steps to a horizontal position and othermeans for automatically retracting the movable steps to their originallocked position when the weight of a user has been removed therefrom andfluid means for braking the retracting movement of said steps.

5. The combination according to claim 4 in which the means for swingingsaid steps include hydraulic apparatus connected thereto.

6. In a safety ladder comprising a pair of opposed longitudinalsupporting members, a set of movable steps normally locked in parallelwith said pair of longitudinal supporting members, means for swingingsaid set of steps to a horizontal position and other means forautomatically retracting the movable steps to their original lockedposition when the weight of a user has been removed therefrom, and fluidmeans for braking the retracting movement of said steps.

References Cited by the Examiner UNITED STATES PATENTS 488,990 1/1893Dormitzer 182161 579,328 3/1897 McConnell 182-161 806,915 12/1905 Reed182-161 1,488,624 4/1924 Sperl 18296 3,012,633 12/1961 Magee 182-96REINALDO P. MACHADO, Primary Examiner.

1. IN A SAFETY LADDER STRUCTURE COMPRISING A PAIR OF OPPOSED,LONGITUDINAL, SUPPORTING MEMBERS, A SET OF MOVABLE STEPS IN SAID PAIR OFMEMBERS, A LINKAGE OPERATIVELY CONNECTED TO THE MOVABLE STEPS TO PROVIDEFOR MOVEMENT OF THE LATTER BETWEEN USABLE AND INOPERATIVE POSITIONS,LOCKING MEANS CONNECTED TO SAID LINKAGE TO LOCK SAID STEPS ININOPERATIVE POSITION, AND MEANS MANUALLY ACTUATED TO SIMULTANEOUSLYRELEASE THE LOCKING MEANS AND OPERATE SAID LINKAGE TO PLACE THE STEPS INOPERATIVE POSITION.